Cowl for oil burning smoke screen devices



\ Aug. 751945. J. TWEEDDALE f 2,381,374

COWL FOR OIL BURNING SMOKE SCREEN DEVICES Filed Jar 1. so, 1941 ZSheets-Sheet 1' v Jbhn I needda/e J. TWEEDDALE COWL FOR OIL BURNING SMOKE SCREEN DEVICES Aug. 1-945.

Filqd Jan. 30 1941 2 Sheets-Sheet 2 Jalm Tyvedda1e 'view taken substantially 44 of Figure 3,

- AT j PAT W o FF ice 'ooWL FOR 011. BURNING" SMOKE. SCREEN r I DEVICES 'JohnTweeddale, Torrance, Calif., assignor to The ica, as trustee 7 Secretary, of War of the United States of Amer 1" Application January 30, 1941;"s ria1 No; 376,711 2 Claims. (01. 98.68)

This invention relates to .a-device adapted for use for producing a smoke screen as a defensive weapon of warfare, and more particularly to a devicewhich may be substituted for the chemical smoke generators used by the United States Army and which are destroyed in the operation;

More particularly, it is an aimof theinvention to provide an oil burning smoke screen device adapted to'burn a low grade'of oil which is readily available in all sections of the country and which will last for a long period of time and which may be used repeatedly to thereby materially reduce the cost of operation, and which will burn for a long period of-time without attention- 'Itis a primaryaim of the invention to provide an oil burning smoke'generator the parts or. which are so constructedin relation 'to'each other that combustion of the oil'inthe reservoir or recep tacleis reduced to aminirnum, thereby permitting a full release without consumption by the burning I oil of carbon particles-resulting fromthe combustion to provide themaximu-m' of smoke, and which'despitethe fact that; combustion is reduced to a-minimum in the generator will, due to the regulation of the air intake thereto, keep the gene erator burningwithoutattention,as long as any fuel remains in the reservoir ,or receptacle.-

Still another aim of the invention is to provide by means of perfectly controlled draft regulation for consumption of the residue which offers a serious problem in most oil burning devices. I H Otherobjectsand advantages of the invention will hereinafter-become-more fully apparent from the followingdescription f thedrawings, which I illustrateia preferred embodiment thereof, and

, wherein:

Figure 8 is a fragmentary vertical sectional view illustrating a'slight modification of the construction of the smoke generator.

Referring more particularly to the drawings, wherein like reference characters designate like or corresponding parts throughout the different views, Ill designates generally the oil burning smoke generator comprising the invention and which includes a reservoir or receptacle H forming a pot in which oil, not shown, is adapted to V be burnt and which is provided with an annular [reservoir II is slightly larger than its bottom.

Figure 1 is a front elevational view of-the oil burning smoke generator, I 1 1 3 Figure 2 is an enlarged horizontal sectional along the plane of the line2-2ofFigure1, J. Q.

Figure 3 is a vertical sectional viewtakensubstantially along the plane of the line 313 of Figure 1, I

,Figure i is an enlarged vertical sectional view taken substantially along the plane of the line takensu-bstantially along the plane of the line 1-1 of Figure 6,

A convex or dome shaped cover I3 is adapted to fit over the upper, open, end of the receptacle Hv and the walllZ thereof,adjacent its upper edge is provided with an outwardly projecting annular b M on which the lower edge 0f th cove)? is adapted to rest. The cover I3 at its apex is provided with an opening 15 having an annular upstanding flange l6 disposed therearound and fora purpose parent; 1

The cover 13 is provided With an opening ll adjacent its lower edge for receiving a down draft tube ,I8which tapers from its enlarged open end I9, as best seen in Figure 6, to its restricted closed end Zll. The down draft tube I8 is adapted to be inserted through the opening I! so that its restricted end will extend into the receptacle II and its enlarged end I9 is sizedv to snugly enage the opening I! and is provided with an annular' outwardly projecting flange 2! for engaging the'outer side of the cover I3, around the opening ,l'l to'form an abutment to prevent the down draft tube |8from being passed entirely through theopening I1. As'best' seen in Figure 3, the downdraft tube I8 is supported by the opening I! so that it is disposed at an oblique angle to the receptacle l l-so that its closed end 20 extends to adjacent the bottom thereof. The tube I8 is provided with elongated openings 22 in opposite sides thereof and. which extend substantially from Theupperend of the tube 7 end to end thereof. I8' is cut on an oblique angle relatively to its longitudinal axisso that when properly positioned is provided with an extending lip 24- which loosely which will hereinafter become ap' A stack 26 which is conical shaped is provided with a restricted end 21 which is sized to frictionally engage around the flange'or collar I6 for mounting the stack 26 on the cover I3. A ring 28 is provided with an annular downwardly open ing groove 29 which is adapted to receive the enlarged upper end 38 of the stack 26 for mount-i ing the ring 28 thereon.

A pair of spaced, substantially parallel.bars3I' are arranged diametrically in the ring 28 an'dare suitably secured at their ends to the inner side of the ring. restricted portion 33, adjacent one end thereof which fits between the bars 3I. Rod 32 is threaded at 34 above and below the restricted portion 33 A rod or shaft 32 is provided witha filled with oil, not shown,-th e closure 23 is swun to an open position for entirely exposing the open end I9 of the down draft tubev I8 after which a lighted taper or an igniting torch can be inserted into the down drtft tube I8 through'its open end I9 for igniting the oil in the pot II. If desired, the smokegenerator I maybe provided With a spark igniterand wick,'such as disclosed in my pending application, SerialNo. 341,549, filed J une 20, 1940, and entitled Smokeless oil burning orchard heaters or smoke generators. A six mile an hour wind is suflicient to turn the vane 44 and e lbow member 36 to hold the end 38 away from for receiving nuts 35 for'clamping the rod ;32 to the bars 3 I An elbow shaped member 36 has an end 3''! disposed in the ring '28 and an opposite end 38which opens outwardly and substantially horizontally. A tube 39 is disposed in the elbow member 36 and is fastened in any suitable manner as by means of welding at 40 atone endthereof to the outer'portion of the elbow member 36v so that thetube 3d extends downwardly therefrom and is positioned to engage the shaft 32 when the endj3l is in engagement with the ring 28. Thetshaft 32 .is-pr.ovided with a restricted portion 4| at its upper; end for engaging an opening 42 in the outer portion of the elbow member 36. It will thus be seen that the elbow member 36 is supported by the connectionof the shaft 32 and the tube 39 which issufliciently loose t permit the end to Swivel in the ring 28. A pair of spaced resilient'fianges 43 project upwardly from theuppermost portion of the elbow member 36, adjacent its-end 38-for frictionally engaging a vane 44 whichis mounted therein and which tapers away from the open end 38 and in the opposite direction thereto; A'rod 45 is secured to the vane 44 and projects; from the tapered 'or'restrictedend 46- thereof andis provided with a threaded free end 4Tfor receiving a weight 48 'which'is provided with a threaded bore 49 for engaging the threaded end 41 for adjustably'mounting the weight 48- relativelyto the rod 45. It willbe apparent that the weight 48 can be adjusted to correctly counterbalance the weight of the vane 44- and the end 38 scarlet the member 38 will be balanced above the stack 26 to permit the tube 39 to rotate-freely en the the wind so as to produce a draft upwardly through the stack 26 to cause air to be drawn downwardlythrou-gh the tube I8 and discharged laterally through its openings 32 to provide sufii ciently combustion to keep the oil burning and yet to so limit the combustion that the carbon particles resulting therefrom will be released without being consumed to produce a maximum ofsmoke. i

It has been discovered as a result of experimenting extensively with the smoke generator that the most efficient smoke output is obtained when the comparative sizes of the parts are sub stantially as illustrated.

Various modifications and changes are contemplated and may obviously be resorted to as only preferred embodiments of the invention have been disclosed.

I claim as my invention:

1. In a device of the character described, a stack, a ring having a downwardly opening groove for engaging the upper end of the stack, a'pair of bars disposed diametrically in the ririgand 'connected thereto, said bars being spaced laterally from each other, a rod having a restricted portion near one of its ends for slid'ably'engaging between the rods, said end of the rod-being threaded, nuts engaging the threaded end above and below the bars for adjustablyclamping the rod thereto, an elbow shaped cowl having one end disposed in said ring, and a tube secured in the intermediate portion of'the cowl'and extending toward and disposed substantially axially of said end of the cowl, the opposite end of. the rod extending into the tube and turn'abl'y engaging the same to rotatably mount the cowl above the stack and to swivelly support said end thereof within the ring.

2. For use with an oil burning smoke screen device of the character embodying 'a pot type burner having a downdraft air inlet, and a vertical stack associated therewith; a cowl assembly comprising an annulus having a downwardly opening groove adapted to receive the upper edge of the stack'wall, an elbow shaped cowl, and supporting means rising from the annulus and upon which the cowl is mounted for rotation, the lower end of the vertical arm of the c'owl and said annulus being concentrically disposed relative to one another so as to form a closed joint between said stack and said cowl which permits the rotation of said cowl. v

' JOHN TWEEDDALE. 

